Dan Hodges is a former Labour Party and GMB trade union official, and has managed numerous independent political campaigns. He writes about Labour with tribal loyalty and without reservation. You can read Dan's recent work here

Ed Miliband is a political Jack Charlton: great at stopping others playing, but can he play himself?

Yesterday a member of Labour’s shadow cabinet put forward an interesting thesis. “There’s a case to be made,” they said, “that Ed Miliband is the most influential opposition leader in British political history.”

Like one of Pavlov’s dogs, I immediately shaped to rebut this misguided theory. But then I paused.

Yesterday, representatives of the big six energy companies appeared in front of the Energy and Climate Change select committee for a roasting over soaring energy bills. In the end they escaped with a light grilling. But the reason they were there was because Miliband had successfully turned the spotlight on energy prices in his conference speech at Brighton last month.

Today is also the day when the proposed Royal Charter on press regulation is supposed to be approved. Again, that Charter is very much Ed Miliband’s creation. It was his decision to demand a judge-led inquiry into phone hacking that lead to Lord Leveson’s report, and that report that has given rise to the Charter. No Miliband, no Charter.

On Sunday the Associated Press announced Syria had filed details of its poison gas and nerve agent programme, along with its initial plan for destroying it, to the Organisation for the Prohibition of Chemical Weapons. Had Ed Miliband not vetoed David Cameron’s support for military strikes on Syria, those strikes would almost certainly have been launched. And there would probably be no talks going on at the moment about the decommissioning of Assad’s remaining chemical stockpiles.

This morning’s papers are also full of the ongoing debate on HS2. And as the Prime Minister himself conceded on Friday, that debate is raging because Ed Miliband has started to raise doubts about whether Labour will back the project. In fact, Government sources have hinted that if Miliband doesn’t offer full support for the scheme, it may well be axed.

It’s possible to question the wisdom of the Labour leader’s stance on each of those issues. The energy price freeze is nothing of the sort. If implemented it would simply be a 20-month energy price hiatus, followed by an energy price rise bombshell that would hammer the budgets of many households. The Royal Charter will formally sound the death knell for over three centuries of press freedom. Assad is currently playing footsie with the UN, but remains free to massacre his own citizens as he does so. And Labour council leaders across the land are warning of the devastating impact HS2 cancellation would have on their regional economies.

But for good or ill, Ed Miliband has directly set the political agenda in a way few opposition leaders have in the past. Which raises the question: if Ed Miliband is such an effective opposition leader, why do people find it so hard to imagine him as an effective Prime Minister?

There is some evidence Labour’s price freeze offer has at least halted Labour’s drift in the polls. But so far there is scant evidence of any radical shift in perceptions of Miliband himself. As Professor John Curtice said, after assessing the state of the three main parties in the aftermath of the conference season, “The public are still far from regarding him [Miliband] as someone whom they regard as a potential prime minister.”

Part of the reason may well be that an ability to “set the agenda” is an overrated political virtue. What Westminster is talking about is not necessarily what the public are talking about. And important though press regulation, Syria and HS2 are, they will not directly shape how people vote in May 2015.

Equally, just because a political party is talking about the things it wants to be talking about, it doesn’t mean it’s talking about the things it should be talking about. One of Ed Miliband’s senior advisers loves quoting from the series Mad Men, where the lead character Don Draper says sagely “If you don’t like what’s being said, change the conversation.” It’s a nice line, and evidence of its influence can be seen in the way Labour has stopped talking about economic growth, and started talking about the cost of living crisis.

But sooner or later, if it wants to be in government, Labour will have to start talking about the economy again. Along with leadership, it is the issue that decides election campaigns. And if you keep changing the conversation too much, people get bored and go off to find someone else to talk too.

Another shadow cabinet member I was chatting to assessed Miliband’s problem like this. “He doesn’t ever build on things. He’ll wait and wait and then at the last moment he’ll jump. Invariably he’ll manage to stabilise his position, but he won’t be any further forward. That’s what he’s done with the energy freeze. He’s back where he started. But more time’s been lost.”

Leadership also involves mounting internal, as well as external, challenges. Miliband has done a good job of defining himself against vested interests outside the Labour family; the press, the banks, the energy companies. But as the re-ignition of the Falkirk scandal has shown, he is much less comfortable at asking his party and movement to challenge itself.

Labour insiders who believed his trade union agenda would prove to be his “Clause 4 moment” are become increasingly fatalistic. “They don’t know where they’re going with that now,” said one MP. “It’s running into the sand.”

Perhaps there is a more simple explanation. Maybe Labour’s leader has effectively found his level. I once saw an interview with Jack Charlton in which he was asked how both he and his brother Bobby had turned out to be such great football players. Jack, one of England’s greatest defenders, responded, “I couldn’t play. Our kid could play. I could only stop other people from playing.”

Maybe Ed Miliband is Labour’s Jack Charlton. He is adept at stopping David Cameron from shaping the game, and can set up Labour for a series of attacks themselves. But he isn’t really comfortable with the ball at his own feet. Or with the goal in his sights.

There may be some truth in the fact Ed Miliband is proving one of the most influential opposition leaders in British history. But he still has a long way to go before he becomes one of our most influential Prime Ministers.